Boot.ini simple or trainwreck?...help please

Hi, I have searched far and wide on my problem but keep going round in circles so here ask for an answer to my own brand of stupid.  

I have xp pro sp3 installed on my C: drive. I was having a minor issue with some long term installed programs so after some lack of success attempted to "repair" said installation. The repair failed and simply installed xp SP2 on another partition. Along with a couple of interrupted (partial) installs on other partitions.

Startup provides 3 options, the 2 partial installs and the working rogue install but NO sign of my previously working C: drive (default) version.

I have access through the "rogue" install by "normal" or "safe" boot. C: Drive and all its folders, installs etc is still there and accessible.

I suspect my solution lays somewhere between boot.ini and bootcfg but it appears that the boot.ini and other entries all point to the 3 rogue installs. The system has 4 drives, partitioned C - J, if the "rogue" drives are disconnected and unseen by the bios the C rive will not boot or repair, attempts to repair halt with the classic "pci.sys" error.

I'm up to 72 hours and counting so would much appreciate help in a positive form, many thanks in advance.